1. Field of the Invention
The invention relates to a technique which adequately ensures the sealing quality at a joint between a lens and a lamp body and makes a mounting groove shallow, to thereby reduce the non-radiating portion of the lens to achieve an attractive appearance and eliminate optical waste.
2. Description of the Related Art
In vehicular lamps, the mounting means for mounting the lens on the lamp body and join them together generally comprises a mounting groove formed on the lamp body and a rib formed on the lens. A sealing material having adhesiveness and a sealing property is interposed between the mounting groove and the rib such that they are fitted and secured to each other.
By way of example, a vehicular lamp a comprises, as shown in FIG. 4, a container-shaped lamp body b opened forward and laterally, and a lens c covering the opening of the lamp body b.
The lamp body b has a mounting groove d formed along a open edge thereof, and the lens c has a rib e formed along a respective peripheral edge thereof. The rib e is inserted into the mounting groove d. In addition, the sealing material f is filled between the mounting groove d and the rib e to secure the lamp body b and the lens c to each other and to fill up the gap therebetween, thus closing the lamp space defined by the lens and the lamp body.
With a prior vehicular lamp a shown in FIG. 4, in order to ensure adequate adhesiveness between the lamp body b and the lens c and keep airtightness in a lamp space, it is required that the lamp body b and the lens c be adhered to each other over at least a certain area. More specifically, the mounting groove d and the rib e must have at least a certain magnitude, so that a section g (referred hereinbelow as "extended section") of the lens, which extends laterally, poses a problem when the vehicular lamp a is put on. Here, light from a light source is intercepted by the mounting groove d, the rib e and the sealing material f to produce a non-radiating, dark portion h (a non-radiating portion) to impair the appearance, and a region of the lens c corresponding to the non-radiating portion h is an optically wasted region.